The number of echoes combined into a single image or image set in multiple echo imaging sequences or echo-train techniques such as rapid acquisition with relaxation enhancement (RARE), fast-spin echo (FSE), and turbo spin-echo (TSE). In RARE imaging, the ETL typically equals the acceleration factor.
As for tooth pain, it is caused by a reaction of the nerves inside a tooth's pulp chamber with the severity dependent upon the type and degree of the stimulus. What follows are some examples of symptoms you may be feeling and their possible causes.
There can be many causes for tooth pain, including dental decay, an injury or infection. If you have tooth pain, read on to find your symptoms, possible causes and treatment options. If you have on-going pain or discomfort, contact your dentist or endodontist. Symptom: Momentary sensitivity to hot or cold foods. Possible problem: If this discomfort lasts only moments, sensitivity to hot and cold foods generally does not signal a serious problem.